v3.26.1
Shareholders' Equity - Accumulated Other Comprehensive Income/(Loss), Net of Tax (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance     $ 124,972  
Other comprehensive income/(loss) adjustments, net of tax $ (944) $ 84 (596) $ 717
Ending balance 122,742 124,096 122,742 124,096
Currency translation        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance (831) (850) (804) (815)
Other comprehensive income/(loss) adjustments, net of tax (46) (35) (73) (70)
Ending balance (877) (885) (877) (885)
Debt valuation adjustment        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance 86 (154) (1,062) (386)
Other comprehensive income/(loss) adjustments, net of tax (806) (162) 342 70
Ending balance (720) (316) (720) (316)
Pension and postretirement liabilities        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance (495) (518) (496) (528)
Other comprehensive income/(loss) adjustments, net of tax 3 13 4 23
Ending balance (492) (505) (492) (505)
Available-for-sale securities        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance (650) (552) 103 (972)
Other comprehensive income/(loss) adjustments, net of tax (94) 273 (847) 693
Ending balance (744) (279) (744) (279)
Cash flow hedges        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance (22) 5 (1) (1)
Other comprehensive income/(loss) adjustments, net of tax (1) (5) (22) 1
Ending balance (23) 0 (23) 0
Accumulated other comprehensive income/(loss)        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance (1,912) (2,069) (2,260) (2,702)
Ending balance $ (2,856) $ (1,985) $ (2,856) $ (1,985)